Jesus Will Return

"29 "Immediately after the distress of those days
   " 'the sun will be darkened,
      and the moon will not give its light;
      the stars will fall from the sky,
      and the heavenly bodies will be shaken.
30 "At that time the sign of the Son of Man will appear in the sky, and all the nations of the earth will mourn. They will see the Son of Man coming on the clouds of the sky, with power and great glory.
31 And he will send his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of the heavens to the other."

The Day and Hour Unknown
36 "No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father. 37As it was in the days of Noah, so it will be at the coming of the Son of Man. 38 For in the days before the flood, people were eating and drinking, marrying and giving in marriage, up to the day Noah entered the ark; 39 and they knew nothing about what would happen until the flood came and took them all away. That is how it will be at the coming of the Son of Man. 40 Two men will be in the field; one will be taken and the other left. 41Two women will be grinding with a hand mill; one will be taken and the other left.